Telephone line dialer and emergency call system

ABSTRACT

Emergency call system by which a caller can automatically call other parties to leave an emergency message, includes an emergency call unit having a memory for storing telephone numbers to be called and the emergency message, an emergency key, and a microprocessor for controlling storage of the numbers and emergency message in the memory, setting each number to be dialed in sequence, delay dialing of each number for a period of time (without first detecting a dial tone) to assure that an outgoing call can be made on the telephone line, and dialing the numbers in sequence upon activation or the emergency key. The emergency call unit starts a transmission of the emergency message to the dialed number to automatically advise of an emergency after a predetermined time after the number has been dialed and no busy signal has been detected during a predetermined time period.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional Application of U.S. applicationSer. No. 11/356,519 filed Feb. 17, 2006 which is incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates generally to a telephone line dialer whichinitiates calls on the telephone line without detecting a dial tone.

The present invention also relates to emergency call systems, and inparticular, to an emergency call system for aiding persons in distress,for example, due to medical, fire, burglary or other emergencies.

BACKGROUND OF THE INVENTION

Emergency call systems are known in which a person in distress can getimmediate help. Specifically, in such systems, the person presses abutton on a pendant which transmits a signal to an alarm in the person'shouse. The alarm then sends a signal to a central station, and a personat the central station must then dial the telephone numbers from aprescribed list in order to obtain aid for the distressed person.

However, such an arrangement is relatively complicated and costly.Specifically, such arrangement operates in a similar manner to a centralburglar or fire alarm in a house, and requires a separate, complicatedwiring assembly for the house, at a considerable cost. Also, such asystem requires that a central station be provided, and therefore, thesubscriber to such a system must pay a monthly fee for such service,adding further to the cost of the system.

Also, a problem with known systems is that if a central station, uponcalling a telephone number of attempts, so that the person in distressdoes not receive aid.

Emergency call systems have therefore been invented which are connectedto the telephone line and enable a caller to automatically call aplurality of other parties to leave an emergency message, sometimes,simply by pressing a button.

Examples of such emergency call systems are disclosed in U.S. Pat. Nos.6,212,260 and 6,614,883, incorporated by reference herein, wherein theemergency call systems include an emergency call unit having a memoryfor storing telephone numbers to be called and an emergency message, anemergency key, and a microprocessor for controlling storage of thetelephone numbers and emergency message in the memory, after the dialtone is obtained, dialing the telephone numbers in sequence uponactivation of the emergency key, starting a transmit of the emergencymessage to the dialed telephone number to automatically advise of anemergency after a predetermined time after the telephone number has beendialed and no busy signal has been detected during a predetermined timeperiod, and restarting the transmit of the emergency message to thedialed telephone number to automatically advise of an emergency afterdetecting each ring-back from each telephone number.

It is now desirable to provide an emergency call system which has a modeof operation which does not require detection of a dial tone to initiatedialing of the telephone numbers, this mode being addition oralternative to operation of the emergency call system using dial tonedetect as disclosed in the '260 and '883 patents.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide anemergency call system that improves on the emergency call systemsdisclosed in U.S. Pat. Nos. 6,212,260 and 6,614,883 while stillachieving the advantages of those emergency call systems, i.e.,eliminating the requirement for a central station, eliminating therequirement for a separate wiring of the person's house, enabling itsuse with a conventional telephone line, enabling continuously calling ofpredetermined telephone numbers until an acknowledgment is received, andwhich is inexpensive and easy to make, install and operate.

It is another object of the present invention to provide a new andimproved emergency call system which is designed to dial presettelephone numbers without first waiting to detect the presence of a dialtone on the telephone line to which the emergency call system isconnected.

It is still another object of the present invention is to provide atelephone line dialer connected to a telephone line and which initiatescalls on the telephone line without detecting a dial tone, yet assuresthat a call made using the dialer will be completed.

In accordance with one aspect of the present invention, an emergencycall system by which a caller can automatically call a plurality ofother parties to leave an emergency message in accordance with theinvention includes an emergency call unit including a memory for storinga plurality of telephone numbers to be called and at least one emergencymessage, an input/output device for connecting the emergency call unitfor making a telephone call, at least one emergency key, and amicroprocessor connected with the memory, the emergency key(s) and theinput/output device. The microprocessor controls storage of theplurality of telephone numbers to be called and the emergency message inthe memory, sets each telephone number to be dialed in sequence, anddials the telephone numbers in sequence upon activation of the emergencykey(s). Before dialing each telephone number, the microprocessor canwithout first detecting a dial tone, delay dialing of each telephonenumber for a period of time to assure that an outgoing call can be madeon the telephone line.

The delay in dialing can be a two-phase delay to account for thepossibility of a previous call not being effectively terminated by thecalling party and the possibility of an incoming call being made to theline during the dialing routine. In the first case, the microprocessordetermines whether a first predetermined period of time has elapsed or aring signal is detected and enables each of the telephone numbers to bedialed, without first detecting a dial tone, only after the first periodof time has elapsed or the ring signal has been detected. The firstperiod of time may be a time set by the telephone company to enable acall terminated by the called party to resume, e.g., a sixteen secondtime period. In the second case, the microprocessor monitors thetelephone line for silence, after determining whether the firstpredetermined period of time has elapsed or the ring signal has beendetected, and enables each of the telephone numbers to be dialed onlyafter a period of silence is detected based on the duration of a quietportion of the ring signal sequence. The period of silence should besufficiently larger than the typical four second quiet portion of a sixsecond ring signal to ensure that no incoming call is being received.

Various situations arising during usage of the emergency call unit andthe telephone or devices associated with the same line are possible anddealt with in accordance with the invention to ensure the ability tomake an outgoing call. For example, when an incoming call to the line ofthe emergency call unit is answered and then terminated, the first delayis required to take care of the possibility of the calling party nothanging up and remaining in control of the line as permitted by thetelephone company (referred to as “calling party control”). After thefirst delay, the second delay is required to ensure the absence ofanother incoming call. If a ring tone is detected after the first delay,then the emergency call unit must continue to monitor the line foradditional ring signals until the time for the second delay, i.e., aperiod of silence on the line, has elapsed. Only at that time, can theemergency call unit effectively seize the line and place the firstemergency call. Satisfaction of both delay conditions should insure thatthe line is clear to make an outgoing call.

Another embodiment of an emergency call system in accordance with theinvention includes in addition to a memory, input/output device and oneor more emergency keys as described above, a first speaker and a firstmicrophone through which a caller can communicate with the called party,a second speaker and a second microphone through which a called partycan communicate with the caller, and a microprocessor which controlsstorage of the plurality of telephone numbers to be called and theemergency message(s) in the memory, sets each telephone number to bedialed in sequence, without first detecting a dial tone, delays dialingof each telephone number for a period of time to assure that an outgoingcall can be made on the telephone line, and dials the telephone numbersin sequence upon activation of the emergency key(s). The microprocessorcan generate the delay in the general manner described above.

In another embodiment of an emergency call system in accordance with theinvention, which may but is not required to include the delay routinedescribed above, the microprocessor is arranged to turn a speakerphoneoff when the telephone is on hook and a call is in progress on thetelephone line upon activation of the emergency key(s), and then proceedwith the delay in dialing. This can be accomplished electronically.

In yet another embodiment of an emergency call system in accordance withthe invention, which may but is not required to include the delayroutine or speakerphone shutoff routine described above, themicroprocessor is arranged to detect an off hook condition uponactivation of the emergency key(s) and electronically bypass the handsetand then proceed with the delay in dialing.

In still another embodiment of an emergency call system in accordancewith the invention, which may but is not required to include the delayroutine, speakerphone shutoff routine or handset bypass routinedescribed above, the microprocessor is arranged to detect an off hookcondition and upon detection thereof, activate a speakerphone aftercompletion of the dialing sequence to enable reception of incomingcalls. Thus, incoming calls can be received in spite of the off hookhandset.

A dialer for making an outgoing call in accordance with the inventionincludes a housing and a communications unit arranged in the housing andcoupled to the telephone line. The communications unit includes amicroprocessor arranged to receive a command to initiate an outgoingcall on the telephone line to a telephone number, without firstdetecting a dial tone, delay dialing of the telephone number for aperiod of time to assure that the outgoing call can be made on thetelephone line, and then dial the telephone number after the delay. Themicroprocessor can generate the delay in the general manner describedabove for the emergency call systems in accordance with the invention.

The above and other objects, features and advantages of the presentinvention will become readily apparent from the following detaileddescription thereof which is to be read in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with further objects and advantages thereof, maybest be understood by reference to the following description taken inconjunction with the accompanying drawings, wherein like referencenumerals identify like elements, and wherein:

FIG. 1 is a block diagram of the emergency call system according to thepresent invention;

FIG. 2 is a top plan view of a keypad that can be used with theemergency call unit having a telephone incorporated integrally therein;

FIG. 3 is a top plan view of a keypad that can be used with the pendant;

FIGS. 4A-4H are flow chart diagrams of the operation of the emergencycall system.

DETAILED DESCRIPTION OF THE INVENTION

The present invention utilizes in large part the emergency call systemdisclosed in U.S. Pat. Nos. 6,212,260 and 6,614,883. Therefore, thedescription of the emergency call system in those patents is repeatedherein.

Before discussing the present invention with reference to the drawings,a brief overview of the invention will be provided. With the presentinvention, when a user is in distress or has an emergency, the userdepresses a key or button on an emergency call unit or on a pendant thatthe user is wearing, with the button that is depressed corresponding tothe situation. For example, if the user has a medical emergency, theuser may depress a key E1 on the pendant. The pendant then transmits asignal to the emergency call unit connected to a telephone line at thelocation of the user. The emergency call unit proceeds to dial, insequence, a plurality of, for example, five, preset telephone numbersthat are stored in a memory in the emergency call unit, with an optionalsixth telephone number being 911. The unit plays a pre-recorded messageregardless of whether the called telephone number is answered or not,and then proceeds to call the next telephone number. In addition, theperson being called has the option of communicating with the caller,replaying the message or stopping further delivery of the message tosubsequent telephone numbers by pressing appropriate keys on the calledperson's telephone keypad.

Thus, rather than requiring a complicated alarm unit which is hard-wiredinto the user's house and rather than requiring the use of a centralstation, the present invention automatically dials preset telephonenumbers and delivers an emergency message for help. In the event thatnobody is available at any of the called telephone numbers to respond,the unit can then be set to dial the emergency telephone number 911.Alternatively, the emergency telephone number 911 can be dialed at adifferent time in the sequence, such as the first, second, third or soon number that is dialed.

Referring now to the drawings in detail, an emergency call system 8according to the present invention includes an emergency call unit 10having a record/call switch 12 which connects to the telephone line ofthe telephone company (TELCO) through a conventional telephone jack, andto which an external telephone unit 14 can be connected through aconventional telephone line. Alternatively, telephone unit 14 can beformed integrally within emergency call unit 10. Record/call switch 12is controlled to switch between a conventional telephone/emergency calluse (CALL MODE) via telephone unit 14 in which telephone unit 14 can beoperated normally and in which emergency call unit 10 automaticallydials various preset telephone numbers during an emergency in order tosupply a prerecorded message, and a RECORD MODE in which varioustelephone numbers and messages can be recorded and whereby telephoneunit 14 is used to record and hear messages and insert telephonenumbers.

The switching of record/call switch 12 is controlled by a REC/CALLswitch on the keypad. ON/OFF control circuit 18 is effectively a powertransistor which creates an off hook condition of telephone unit 14, andsupplies a signal corresponding thereto to microprocessor 16.

A message storage unit 20 is provided for storing recorded messages andfor supplying respective stored messages to the telephone line throughan audio interface 22, ON/OFF control circuit 18 and record/call switch12. In response to activation by a user, microprocessor 16 sends acontrol signal to message storage unit 20 to cause message storage unit20 to supply a pre-recorded message to the telephone line when anemergency telephone number is dialed, as will be explained in greaterdetail hereinafter. Alternatively, a user can play back a recordedmessage to check the same, and this is also controlled by microprocessor16 which causes message storage unit 20 to supply the recorded messageto an audio control circuit 24, which selects whether the audio messageor a DTMF signal is supplied to the speaker, and then supplies theanalog signal to a loudspeaker 26 or telephone 14 built into emergencycall unit 10.

The upper surface of the housing for emergency call unit 10 contains akeypad 30 with a plurality of keys or buttons, as shown in FIG. 2.Specifically, there is at least one emergency key. In FIG. 2, threeemergency keys are shown, namely, key E1 for a medical emergency, key E2for a fire emergency and key E3 for a burglary emergency. However, thenumber of keys may vary within the scope of the present invention.Alternatively, one key can be provided which toggles through thedifferent emergency situations, along with a separate send key (notshown) for sending a message corresponding to that key. In such case, aseach key is toggled, a message can be played to indicate the particularkey.

In addition, there is a record key REC for recording a message to bestored in message storage unit 20, a playback key PLAY for playing backa pre-recorded message storage in message storage unit 20, a store keySTORE for storing telephone numbers and a key 911 for selecting anautomatic emergency number 911. There is also a REC/CALL toggle key forcontrolling operation in a RECORD mode or a CALL mode. Keypad 30 isconnected with microprocessor 16 for supplying appropriate signalsthereto, as will be described hereinafter.

The numeric keys 0-9 and the star (*) key and pound (#) key of telephoneunit 14 can be used to enter the appropriate digits and other commandswhere telephone unit 14 is a separate unit from emergency call unit 10.Alternatively, telephone unit 14 can be formed integrally with emergencycall unit 10, and in such case, numeric keys 0-9 and the star (*) keyand pound (#) key are formed on keypad 30 of emergency call unit 10, asshown in FIG. 2.

A telephone number memory 32 is also connected with microprocessor 16and stores a plurality of, for example, up to five telephone numbers,although the number of telephone numbers that can be stored can varywithin the scope of the present invention. Alternatively, telephonenumber member 32 and message storage unit 20 can be combined in a singlememory. Reference in the claims to a memory for storing the telephonenumbers and emergency messages refers to either a single memory orseparate memories.

Power can be supplied to emergency call unit 10 by a battery 34 or apower line via a conventional power adapter 36. The outputs of battery34 and power adapter 36 are supplied to a power select circuit 38 thatselects power adapter 36 as a default, and which selects battery 34 whenthere is no power from the output of power adapter 36. The output ofpower select 38 is supplied to a power control circuit 40 that suppliespower to microprocessor 16. In addition, power from power select 38 issupplied to record/call switch 12.

When an appropriate key E1, E2 or E3 from keys 30 is depressed,microprocessor starts reading out the telephone numbers one by one frommemory 32 and supplying the same to a DTMF encode circuit 42 which thensupplies an appropriate DTMF encoded signal for that telephone number tothe telephone line through audio interface 22, ON/OFF control 18 andrecord/call switch 12. At the same time, microprocessor 16 controlsmessage storage unit 20 to read out the appropriate pre-recordedmessage, which is also supplied to the telephone line through audiointerface 22, ON/OFF control 18 and record/call switch 12.

The supply of the message to the called person can occur in any one ofthree ways, as follows.

In a first mode of operation, the pre-recorded message is read out evenwhile the telephone being dialed is still ringing. For example, thesystem can wait a predetermined amount of time, for example, 3 seconds,after the telephone number of the called party is dialed. When a personpicks up, the pre-recorded message may be in the middle of a message,although the called person has the option to replay the message. Thepre-recorded message can be played once for each telephone number, sothat the person picking up the telephone merely needs to continuelistening to hear the entire message. In this manner, there is no delayfrom the time that the person answers the telephone. However, it ispreferable for the message to be played twice once a telephone is pickedup or after an answering machine answers. Since the emergency andpre-recorded instructional messages are played twice, the called partywill hear both messages at least once. The advantage of this method isthat there is no need for any detection circuit in emergency controlunit 10 to detect when a telephone is answered, thereby greatlysimplifying the circuitry and rendering system 8 less costly. The calledperson also has the option of hitting a key to replay the message. Inthis regard, a jumper toggle key J1/J2 is provided. When depressed tothe J1 side, only one message is played, and when depressed to the J2side, the message is played twice.

In a second mode of operation, the system starts playing the message ashort time after the telephone number is dialed and no busy signal isdetected in a predetermined time period. The system then detects thering-back signal from the next ring and starts replaying the selectedemergency message a predetermined time, for example, 2 seconds, afterthe end of the ring-back signal. The reason for not requiring aring-back detection for the start of the message is that the calledperson can pick up the telephone before a first ring-back. If the systemrequired a ring-back to start playing the emergency message, noemergency message would ever be played.

In this case, the ring sequence is generally about 2 seconds of ringtone separated by 4 seconds of silence. If nobody answers and a secondring-back signal is detected, the message that is being played ishalted, and is then restarted after the same predetermined time of 2seconds after the detection of the second ring-back signal. Thiscontinues until a predetermined number of, for example, five, ring-backsignals are detected. At this time, the system determines that there isnobody at the called telephone number that will answer and thereby hangsup and dials the next telephone number on the list. This method has theadvantage that none of the message is lost when the telephone is pickedup, since the message starts replaying after each ring-back signal isdetected. However, the called person does have the option of replayingthe message, as described in more detail hereinafter.

The third method of operation relies on the detection of speech from thecalled party to start the playback of the messages. In this case, theplayback may start after a short delay of, for example, 1 or 2 seconds,after the speech is detected. In the event that an answering machine isprovided, the system can replay the messages twice after speech isdetected. Thus, the first message will be lost to the answering machinesince the called party's message will be playing, but the secondplayback will be recorded on the called party's answering machine. Withthis method of operation, the system will still detect the ring-backsignals and hang up after the detection of five ring-back signals, withthe next telephone number then being dialed.

Any conventional speech detect on arrangement can be provided, forexample, the speech can be detected by the microprocessor based onvarious factors, such as frequency of the signal, spacings betweenportions of the signals, etc.

As discussed above, when emergency call unit 10 dials out a telephonenumber from the telephone numbers stored in memory 32, and a personpicks up the telephone, the prerecorded emergency message is played. Atsuch time, the called person can merely listen to the message and thentake appropriate action. Alternatively, the called person can request aplayback of the message by pressing a predesignated key, such as the “9”key on the person's telephone keypad. The person can also end theplayback of the pre-recorded message and send a signal to emergency callunit 10 to prevent further telephone numbers being dialed, for example,by pressing a predesignated key, such as the “8” key on the person'stelephone keypad. Also, the called person can set up a communicationwith the caller through speaker 26 and a microphone 58 connected withaudio control circuit 24, by depressing a predesignated key, such as the“7” key. In such case, the tone for the number 7, 8 or 9 is suppliedover the telephone line and through record/call switch 12, ON/OFFcontrol circuit 18 and audio interface 22 to a DTMF decode circuit 44which decodes the signal and supplies a signal corresponding thereto tomicroprocessor 16. If the “7” key has been depressed, communication isestablished between the parties. If the “8” key has been depressed,microprocessor 16 stops the dialing of further telephone numbers. If the“9” key has been depressed, microprocessor 16 controls memory storage toreplay the prerecorded message.

As an alternative and more preferred embodiment, if the “8” key isdepressed by a called party, the system will continue to dial theremaining telephone numbers once after the called party that depressedthe “8” key disconnects. However, if no called party depresses the “8”key, the system will continue to dial all of the telephone numbers in arepeating sequence for a predetermined amount of time, for example, 15minutes, regardless of whether the message is received by any or all ofthe called parties. This provides some assurance to the caller indistress that one of the called parties has received and message andwill take some action. In other words, it provides an acknowledgmentthat the message has been received by a live adult party. For example, amessage received by an answering machine or a small child is a passiveresponse or answer to the emergency message and is of minimum value interms of responding to an emergency. Thus, if five answering machinesreceive the message, the system will still dial the telephone numbers insequence for the predetermined time a further attempt to connect with alive person.

As discussed above, if the “7” key has been depressed, communication isestablished between the parties.

In one mode of operation, the called party controls the speaking andlistening. Thus, for example, if the called party thereafter presses“1”, the called party can listen for a preset time period, for example,30 seconds, and if the called party presses “2”, the called party canspeak for a preset time period, for example, 30 seconds. Any time that“1” is pressed during the aforementioned time periods, the called partystarts a new 30 second time period for listening, and if “2” is pressed,the called party starts a new 30 second time period for speaking. Thereason that the called party has control over who speaks and who listensis for a number of reasons. First, the caller may be injured and may notbe able to press the buttons on the telephone. Also, the caller may bein panic, and a person in panic may not have the frame of mind todetermine which button to depress to speak or listen.

In another mode of operation, the operation of speaking and listening iscontrolled automatically to change over from one to the other afterpreset periods of time. For example, after the emergency andinstructional messages are played out, a beep is provided whichindicates that the calling party is permitted to speak for 15 seconds,and then another beep is provided which indicates that the called partyis allowed to speak for 15 seconds. Two further 15 second intervals canbe provided thereafter, one for the caller and the other for the calledparty. After the time periods for speaking and listening have expired,the telephone call can be automatically terminated unless the “9” key isdepressed by the called party to request a replay of the messages.

In a further embodiment, if a called person depresses “7”, both partiescan speak to each other for a fixed period of time, or without a timelimitation, as with a standard speakerphone. This can occur without anemergency message being played at all.

Although the present invention has been discussed with reference to thedepression of any of keys E1, E2 or E3 on keypad 30, the emergency callsystem 8 of the present invention can be activated from a locationremote from emergency call unit 10. For example, emergency call system 8can include a pendant 46 or other remote unit worn by the user andhaving one or a plurality of keys 48. For example, since the only timethat a caller may need the pendant is during a medical emergency, onlykey E1 is preferably provided thereon, as shown in FIG. 3.Alternatively, all three keys E1, E2 or E3 can be provided. In addition,pendant 46 includes a cancel key CANCEL in the event that key E1 isinadvertently depressed, as shown in FIG. 3. A similar key is preferablyprovided on the main unit also. Cancel key CANCEL can also be used bythe caller to shut down the entire system at any time. Pendant 46includes a transmitter 50 with an antenna 52 which transmits a signalcorresponding to the depressed key 48 to a receiver 54 of emergency callunit 10, having an antenna 56. Receiver 54 supplies the received signaldirectly to microprocessor 16 in order to start the above emergency calloperation.

Referring now to the flow chart diagram which continues across FIGS.4A-4G, and initially to FIG. 4A, it is assumed that power for emergencycall unit 10 is turned on and switch REC/CALL is in the CALL position orRECORD position.

In step 100, in the CALL position when one of the emergency keys E1, E2or E3 in depressed, power is applied to emergency call unit 10 and inthe RECORD position, by the toggle switch REC/CALL on the keypad beingplaced into the RECORD position, power is turned on for the RECORD MODE,whereupon microprocessor 16 is initialized in step 102, followed byinitialization of control registers of microprocessor 16 in step 104,that is, the input/output (I/O) of microprocessor 16, and theninitialization of flags in the software stored in memory inmicroprocessor 16 in step 106. Thereafter, microprocessor 16 issynchronized with a 25 msec clock signal in step 108. Microprocessor 16then determines if the CALL/REC key is in the CALL position or in theRECORD position. In the CALL position, the user can use telephone unit14 in a conventional manner, and in addition, if one of the emergencykeys E1, E2 or E3 is depressed, microprocessor 16 will operate in theCALL MODE. In the RECORD position, telephone unit 14 is disabled fromthe telephone line, and if one of the keys REC, PLAY, STORE or 911 isdepressed, microprocessor 16 will operate in the RECORD MODE, as will beexplained hereinafter.

The RECORD MODE will first be described. If the CALL/REC key is placedin the RECORD position, a message can be recorded or played back,telephone numbers can be stored or deleted, and a 911 telephone numbercan be enabled or disabled. In this mode, emergency call unit 10 isconnected with telephone unit 14 to enable use of numeric keys 0-9 * and# on telephone unit 14 for recording purposes, in step 112, in the eventthat telephone unit 14 is a separate unit.

Referring now to FIG. 4B, power to the latch circuit of microprocessor16 is then cleared in step 114, followed by reading of a depressed keyin step 115. It is then detected in step 117 if this depressed key is anemergency key E1, E2 or E3. If yes, the process then continues toreading of one of the keys REC, PLAY, STORE and 911 upon depression ofthe same, in step 116. If no in step 117, the process returns to step104. In step 118, it is determined if the key that has been depressed isthe record key REC for recording a message to be stored in messagestorage unit 20. If yes, the process continues to step 120 in FIG. 4Cfor the sub-process of recording a message to be sent during anemergency.

In step 120, a predetermined message time out is set in microprocessor16, that is, a maximum length of the message to be recorded. Then, instep 122, the message address is set in message storage unit 20 wherethe message to be recorded will be stored. This depend upon which keyE1, E2 or E3 was initially depressed. In other words, a first address isused for a message corresponding to key E1, a second address for amessage corresponding to key E2 and a third address for a messagecorresponding to key E3. Thereafter, in step 124, power is supplied tomessage storage unit 20 in order to begin storing the message. Whilerecord key REC is maintained in a depressed condition, the user recordsthe message. In step 126, it is determined if the message time out hasbeen reached. If yes, the recording process is stopped, message storageunit 20 is powered down in step 129 and the process returns to the inputof step 104 of FIG. 4A. If not, in step 128, it is determined if therecord key REC is still held down. If record key REC is released, therecording operation is completed and the process returns to step 104after powering down message storage unit 20 in step 129. If the recordkey REC is still held down, the process returns to the input of step 126to continue recording the message. This loop continues until there iseither a time out in step 126 or the record key REC is released in step128.

Returning to FIG. 4B, if it is determined that the record key RECORD isnot depressed in step 118, the process continues to step 130 where it isdetermined if the playback key PLAY has been depressed. If yes, theprocess continues to step 132 in FIG. 4D. Specifically, in step 132, themessage address corresponding to the emergency key E1, E2 or E3 that hasbeen depressed, is set up in microprocessor 16. Thereafter, in step 134,power is supplied to message storage unit 20, and then in step 136,there is playback of the stored message from message storage unit 20corresponding to the emergency key E1, E2 or E3 that has been depressed.After the message has been played back, message storage unit 20 ispowered down in step 138. The process then returns to step 106 in FIG.4A. An alternate implementation is to use a slide switch for enabling ordisabling 911.

Returning to FIG. 4B, if it is determined that the playback key PLAY isnot depressed in step 130, the process continues to step 140 where it isdetermined if the key 911 has been depressed. If yes, the user will thendepress the star (*) key on telephone unit 14 or the pound (#) key ontelephone unit 14 to enable or disable 911 as a telephone number to becalled in the event of an emergency. Specifically, microprocessor 16will read the star (*) or pound (#) key depressed on local telephone 14in step 142 in FIG. 4E. It is next determined if the star (*) key hasbeen depressed in step 144. If yes, 911 is enabled as a telephone numberto be called in the event of an emergency in step 146, and the processreturns to step 104 in FIG. 4A. If no, it is next determined if thepound (#) key has been depressed in step 148. If yes, 911 is disabled asa telephone number to be called in the event of an emergency in step150, and the process returns to step 104 in FIG. 4A. If no, the processreturns to step 104 in FIG. 4A.

Returning to FIG. 4B, if it is determined that the key 911 is notdepressed in step 140, the process continues to step 152 where it isdetermined if the store key STORE has been depressed, in order to storetelephone numbers to be dialed in the event of an emergency. If no, theprocess returns to step 116 where the above processes are repeated.

Before discussing the following steps, it is noted that the system canbe used to dial a telephone number of a residence, central location orthe like to leave an audio message, and can also send the caller'stelephone number to a pager, rather than leaving an audio message. Anarrangement is required to distinguish between the two, so that thesystem knows when to send an audio message and when to send a pagertelephone number. Generally, as will now be discussed in relation toFIG. 4, after the initial entering of the storage operation, a telephonenumber to be dialed for leaving an audio message or a telephone numberto a pager is stored in any of five locations 1-5.

The caller sets the telephone numbers for leaving an audio message byfirst entering the storage location 1-5, followed by depression of thepound (#) key, followed by entering of the telephone number to bedialed, and finally ending by depressing the pound (#) key again, thatis, the sequence includes (storage location 1-5), # (telephone number),#. For setting a pager telephone number, after the initial entering ofthe storage operation in step 152, the caller sets this telephone numberby first depressing the pound (#) key, followed by the storage location1-5, followed by depressing the pound (#) key again, followed byentering of the pager telephone number to be dialed, and finally endingby depressing the pound (#) key again. The telephone number that is sentto the pager is the caller's telephone number which the caller sets inthe system in location 6. In other words, for a pager operation, thedistinction is the depression of the pound key (#) before the storagelocation.

Thus, if yes in step 152, the user will then depress a key in step 154in FIG. 4F. In step 156, it is detected if this is the pound (#) keythat has been depressed in order to set a pager telephone number. If yesin step 156, a pager flag is set in step 157 to denote that the numberto be stored is a pager number to be dialed. The process then returns tostep 154 where the user again depresses a key. In step 156, it isdetected if the key is a pound (#) key. Since it will be a number key,the process continues to step 158 where it is detected whether thedepressed key is a number from 1 through 6. If no, the process returnsto step 154. If the user depresses 1-5, this corresponds to a storagelocation for a telephone number to be dialed. If the user depresses 6,this corresponds to the telephone number of the user to be sent to thepager. If yes, in the next step 160, microprocessor 16 retrieves thenext depressed key by the user, and then, in step 162, determines ifthis key is the pound (#) key. If not, the process returns to step 160until the user presses the pound (#) key. If yes, any telephone numberstored in a temporary storage area is erased during the next step 164.The next key that is depressed is then read in step 166, and in step168, it is determined if this key is the pound (#) key. If not, it isdetermined if the depressed key is a numeric key 0-9 in step 170. Ifnot, the process returns to step 166. If yes, however, the processcontinues to step 172 where the digit 0-9 corresponding to the depressedkey is stored in a temporary memory buffer. In the next step 174, it isthen determined if eleven digits have been read. If not, the processreturns to step 166 to read the next depressed key.

The process for reading all of the digits for a particular telephonenumber ends either when the pound key (#) is depressed as the next keyin step 166 and detected in step 168, or when twelve digits or howevermany digits the telephone system requires, have been read, as detectedin step 174. Thereafter, an address in memory 32 is obtained for storingthe digits of the telephone number (1-6) in step 176, and the digits forthat telephone number are stored in memory 32 at that address in step178. The process then returns to step 104 in FIG. 4A.

Thus, with the present invention, a first telephone number whichprovides an audio message to a called telephone is inserted by the keys1-5, #, phone number, #, while a telephone number which dials a pagernumber is inserted by the keys #, 1-5, #, phone number, #. If the usermakes a mistake while entering a telephone number, the user can depressthe star (*) key to reset the operation for re-inputting the telephonenumber and location.

It will be appreciated that there is a variation in the method ofoperation of different paging systems. Some systems will provide asingle ring-back tone followed by three or four beeps. Others onlyprovide the three or four beeps. It may not be necessary to detect thebeeps at all. The present invention looks for a ring-back. If none isfound, the caller's telephone number will be sent to the pager after adelay of, for example, approximately 5 seconds. In this regard, it ispointed out that the time between ring-back tones is four seconds.

To delete a telephone number from memory 32, the first key that isdepressed and read in step 166, before any digit is read, is the pound(#) key. This is detected in step 168. Since no digits have beenentered, the telephone number corresponding to the location (1-6) iscleared and no new number is stored in place thereof, therebyeffectively deleting the telephone number from memory 32.

The above operations describe the RECORD mode in which the emergencymessages and telephone numbers are recorded or deleted.

For the CALL MODE, REC/CALL switch 12 is set to the CALL MODE by togglekey REC/CALL on keypad 30, and this is sensed in step 110. In this mode,one of the three emergency calling dialing and message playing sequencesis initiated by depressing one of the three emergency call keys E1, E2or E3 either on emergency call unit 10 or on pendant 46. Thereafter,emergency call unit 10 will automatically dial the associated set offive telephone numbers, plus 911 if this is enabled. When dialingstarts, a recognition signal, such as a tone or voice, is provided tothe caller to acknowledge the operation of the system. After eachtelephone number is dialed, the associated emergency message is played,once or twice per user selection depending upon the position of jumperkey J1/J2, followed by a standard message that provides furtherinstructions to the called party. By depressing the appropriate key (7,8 or 9, for example), the called party can either converse with thecaller, acknowledge the emergency situation and shut down the emergencydialer, or repeat the emergency message. The middle operation willprevent other telephone numbers from being dialed, although this isoptional. Alternatively, one or more other numbers can still be calledonce. If no response is obtained by the emergency call unit 10 within aprescribed time, for example, 10 seconds, the emergency dialer will hangup and try the next telephone number in the sequence.

Specifically, after the DIAL mode is sensed in step 110, the emergencykey E1, E2 or E3 is read in step 180 (FIG. 4A) and it is determined if avalid key has been depressed. Specifically, the emergency key E1, E2 orE3 should be held down for approximately one-half second. This operationapplies power via power control 40 to emergency call unit 10. Afterpower is applied, to be a valid key depression, the emergency key mustbe held for an additional predetermined time period of, for example,25-50 msec. in order to determine that there has not been an accidentalflick or depression of the emergency key. In this regard, microprocessor16 senses the emergency key held down and then waits for thispredetermined time period of 25-50 msec. and checks again if theemergency key is still depressed. If not, it is determined to be anaccidental flick of the emergency key, and thereby a false key wherebypower is turned off in step 181 in FIG. 4A. If the emergency key isstill depressed after the second check, it is determined to be a validdepression of the emergency key, and the process continues to step 182in which power is supplied to a latch circuit of the microprocessor 16.

Thereafter, referring to FIG. 4G, microprocessor is set in step 184 toretrieve the first telephone number to be dialed.

It is then necessary for the emergency call unit 10 to detect thepresence of a dial tone on the telephone line to enable the outgoingcall to the first telephone number to be properly made (the dial tonedetect mode), or in the alternative, wait a sufficient amount of time tobe certain that an outgoing call can be made while not taking steps tofirst detect the presence of a dial tone (the delay mode). The sameanalysis applies each and every time the emergency call unit 10 ispreparing to dial a subsequent telephone number. The first situation isshown in the flow chart in FIG. 4G while the second situation is shownin the flow chart in FIG. 4H.

In the first situation, emergency call unit 10 provides an off hookcondition in step 185 to obtain a dial tone. Then, there is a delay ofone second in step 186, followed by the start of a five second timer instep 188. It is then determined if there is a dial tone in step 190. Ifnot, it is determined in step 192 if the five second time period hasexpired. If not, the process returns to step 190. If yes, emergency callunit 10 hangs up in step 194, waits two seconds in step 196, and thenreturns to step 185.

If a dial tone is detected in step 190, the first telephone number to bedialed in association with the emergency key that has been depressed, isretrieved from memory in step 198, and then, this telephone number isdialed in step 200. Steps 185, 186, 188, 190, 192, 194 and 196 thereforefunction as a dial tone detect routine which serves to determine thepresence of a dial tone on the telephone line.

In the second situation, the delay mode, instead of initially detectinga dial tone to determine the ability of the emergency call unit 10 toeffectively make an outgoing call, the emergency call unit 10 isdesigned to dial each preset telephone number after a sufficient amountof time has elapsed to be certain that an outgoing call can effectivelybe made, i.e., the telephone line is determined to be clear to make anoutgoing call. The delay mode can be programmed into microprocessor 16instead of or in addition to the dial tone detect mode.

A routine is therefore programmed into the microprocessor 16 to assurethat a telephone call will not be initiated by the emergency call unit10 if the telephone is subject to calling party control (when theprevious call has not been effectively terminated by the calling party)and if a telephone call is incoming.

Regarding the first criteria, during telephone usage, there is apossibility that an outgoing call cannot be made because a previouslycompleted call has not been effectively terminated. For example, if atelephone call is made to the line on which the emergency call unit 10is connected and is answered on an extension, when the extension phoneis subsequently hung up, a telephone connection can be re-establishedwith the other party for a period of time. Similarly, if a telephonecall on that line is answered by an answering machine, when theanswering machine finishes its operation and hangs up, but the callingparty does not hang up, the telephone connection can be re-establishedfor a period of time.

The reason for the telephone connection being re-established on thetelephone line after the extension phone is hung up or the answeringmachine finishes its operation is because the telephone company'scentral office allows a calling party control over the call (“callingparty control”). In the extension phone situation, if the calling partydoes not hang up, then when a phone or device associated with the sameline as the extension phone, or even the extension phone itself, seizesthe line to make a call after the extension phone has been hung up, theconnection to the calling party will be re-established. In the answeringmachine situation, if the calling party does not hang up, then when aphone or device associated with the same line as the answering machineseizes the line to make a call after the answering machine finishes itsoperation, the connection to the calling party will be re-established.

Indeed, the central office may not disconnect the called party from theline for a period of time up to sixteen seconds so that at any timeduring these sixteen seconds, if a telephone or device connected to theline to which the called party was connected attempts to seize the line,the call can be resumed (as if it was never interrupted). For the sakeof simplicity, a sixteen second time period will be used below; however,the time period can be anywhere from about eight second to about twentyseconds, as determined by the telephone company.

The routine programmed into the microprocessor 16 provides for a delayin the dialing routine which is at least equal to the time period set bythe telephone company to allow a called party to resume a call.Specifically, with reference to FIG. 4H which shows a non-limiting flowchart of one manner to incorporate a delay into the dialing routine, themicroprocessor 16 of the emergency call unit 10 is set in step 184 forthe first telephone number to be dialed. Emergency call unit 10 thenissues a local audio and/or visual alarm in step 250. A timer is startedin step 252 to keep track of a delay time before the expiration of whicha telephone number will not be dialed. Next, in step 254, the telephoneline is checked to determine if all of the telephones and devicesconnected to the phone line are on hook, i.e., the “On Hook” condition.The emergency call unit 10 will continuously check until an “On Hook”condition is detected. If a device connected to the phone line isoff-hook, the timer will be restarted in step 252.

When the “On Hook” condition is detected, the timer is checked in step256 for the sixteen (16) second delay or time out limit (the exactduration of this delay is variable depending on the delay set by thetelephone company). If the time limit has not yet been reached, theemergency call unit 10 looks for the standard ring signal in step 258.If no ring signal is detected, the unit returns to the “On Hook” checkin step 254, and the process continues until an “On Hook” condition isdetected and there is a ring signal or an “On Hook” condition isdetected and sixteen seconds have elapsed.

This part of the delay routine prevents the emergency call unit 10 fromattempting to initiate a call during the sixteen second delay periodduring which an attempt at making a call (by seizing the line inpreparation for an outgoing call) after a previous call was notterminated by the calling party will be construed as an attempt toresume the previous call.

Moreover, this sixteen second delay is further required to account for asituation in which a telephone or other device connected to the line towhich the emergency call unit 10 is also connected has answered a call.In this case as well, if the telephone line is seized to make anoutgoing call within sixteen seconds of the termination of the previouscall, then the previous call will resume. Thus, the sixteen second delayis always applied to ensure that there is no possibility to resume aprevious call.

Once a sixteen second delay incorporated microprocessor 16 has elapsed,it must further be assured that there is no incoming call since if theemergency call unit 10 attempts to seize the line after the sixteensecond delay while a call is incoming, it would inadvertently “answer”the incoming call.

Therefore, the emergency call unit 10 is preferably designed viaprogramming of the microprocessor 16 in the delay mode to monitor thetelephone line for a period of silence greater than the period ofsilence in the ring signal sequence indicative of an incoming call,which is typically a ring signal of four second off sequence following atwo second on sequence for a total ring signal sequence of six (6)seconds. If there is a period of silence larger than the four secondquiet period with the six second ring signal sequence, it is fairlycertain that there is no incoming call. The period of silence withineach ring signal sequence can be altered to a different time perioddepending, for example, on the ring signals used in the location inwhich the emergency call unit 10 is used and the configuration oftelecommunications equipment operating the telephone line to which theemergency call unit 10 is connected. The period of silence is typicallyfour seconds so that a period of silence greater than four seconds isindicative of the absence of an incoming call. For the sake ofsimplicity, a six second period of silence or delay will be used in thedescription below.

To implement this six second delay, after the sixteen second delaydescribed above to prevent resumption of a previous call in view ofcalling party control, the emergency call unit 10 starts a timer in step260 whose limit is six seconds. Similarly, if a ring signal has beendetected in step 258, the unit starts the same six second timer. Next,in step 262, the emergency call unit 10 checks the telephone line todetermine if any phone or device connected to the telephone line is offhook, i.e., the “Off Hook” condition. If the phone line is in the “OffHook” condition, the timer is restarted in step 260.

The emergency call unit 10 will continuously check until an “On Hook”condition is detected. When the “On Hook” condition is detected, thetimer is checked in step 264 for the six second time limit. If the timelimit has not yet been reached, the unit looks for the standard ringsignal in step 266. If no ring signal is detected, the unit returns tothe “Off Hook” check, and the process continues until an “On Hook”condition is detected and there is no ring signal for six seconds. If aring signal is detected prior to the expiration of the six second delay,the six second timer is restarted, and the sequence of On Hookdetermination, timer restart and ring signal determination is repeated.

If the time limit is up (without having detecting a ring signal andwithout having detected an “Off-Hook” condition), the emergency callunit 10 now goes Off Hook in step 268, waits for a specified delay timeto allow the dial tone to appear in step 270, and then continues byretrieving the phone number as shown in step 198 and dialing theretrieved number in step 200 (after which the method proceeds asdescribed below with reference to FIG. 4G).

Referring back to FIG. 4G, after the first telephone number has beendialed in step 200 (having proceeded along the flow chart shown in FIG.4G or the alternative shown in FIG. 4H), it is then detected in step 201whether the pager flag has been set. If no, the process continues tostep 202. If yes, the process continues to step 203 where the systemwaits a predetermined amount of time, for example, up to five seconds toaccount for pager beeps. Then, the caller's telephone number stored inlocation 6 is sent to the pager number that has been dialed in step 205.The process then continues to step 212.

In step 201, if the pager flag is not set, the appropriate pre-recordedemergency message from message storage unit 20 is read out in step 202according to one of the three methods discussed above, and may occureven while the telephone being dialed is still ringing. Preferably, thepre-recorded message is played once for each telephone number, and thisis determined by the jumper key J1/J2, so that the person picking up thetelephone merely needs to continue listening to hear the message. Inthis manner, there is no delay from the time that the person answers thetelephone. Generally, a message will start out with words such as“EMERGENCY. EMERGENCY”, followed by the caller's pre-recorded message,so that the person picking up will not miss essential parts of themessage.

The advantage of sending the message while the telephone is stillringing is that there is no need for any detection circuit to detectwhether the called telephone is answered, thereby greatly simplifyingthe circuitry and rendering system 8 less costly.

However, it is also possible for system 8 to be set up so that themessage is only played after a telephone is picked up or after ananswering machine answers, and this would require such detectioncircuitry, as discussed above.

Following playback of the recorded emergency message, a secondinstruction message is played back in step 204, which instructs thecalled person as to various options that can be taken by depressingappropriate keys. In the event of a pager number being dialed, thecaller's telephone number is sent to the pager instead of the emergencymessage in step 202 and the instruction message in step 204. A tensecond timer is then started in step 206 to give the called person anopportunity to take any of the various actions. In step 208, it isdetermined if the called person has depressed a key on the calledtelephone unit. If no, it is determined if the ten second time periodhas expired in step 210. If no, the process returns to step 208. If yes,emergency call unit 10 hangs up in step 212, and waits for a delay timein step 214. It then determines in step 216 if a total time period, forexample, one-half hour has elapsed. If yes, it hangs up in step 218. Ifno, it sets up microprocessor 16 to dial the next telephone number instep 220. Thereafter, the process returns to step 185. Alternatively,steps 216, 218 and 219 can be eliminated, and the system can dialforever until someone disables the system.

Instead of the process returning to step 185 after setting themicroprocessor 16 to dial the next telephone number according to theflow chart shown in FIG. 4G (using a dial tone detection routine), theprocess can return to step 272 according to the flow chart shown in FIG.4H (wherein no initial dial tone detection is used). As shown in FIG.4H, after setting the microprocessor 16 to dial the next telephonenumber in step 220, the emergency call unit 10 starts a timer in step272 whose limit is six seconds (or any period of time greater than thefour second period of silence within a six second standard ringsignal-again, for the sake of simplicity, a six second delay will beused). Next, in step 274, the emergency call unit 10 checks thetelephone line to determine that any and all telephones and devicesconnected to the telephone line are on hook, i.e., the “On Hook”condition. If a telephone or device is not in the On Hook condition, theprocess proceeds to step 252 to provide for the sixteen second delay andsubsequent six second delay to assure that a previous call will not beresumed and an incoming call will not be answered.

When the “On Hook” condition is detected in step 274, the timer ischecked in step 276 for the expiration of the six second time limit. Ifthe time limit has not yet been reached, the emergency call unit 10looks for the standard ring signal in step 278. If no ring signal isdetected, the emergency call unit 10 returns to the “On Hook” check, andthe process continues until an “On Hook” condition is detected and thereis no ring signal for six seconds. If a ring signal is detected, the sixsecond timer is restarted in step 272, and the sequence of On Hookdetermination, timer restart and ring signal determination is startedagain.

If the time limit is up, the unit goes Off Hook in step 268, waits formspecified delay time to allow the dial tone to appear in step 270, andthen continues by retrieving the phone number as shown in step 198 anddialing the retrieved number in step 200. The process continues asdescribed above.

Referring back to FIG. 4G, if a remote key has been operated by thecalled person in step 208, it is first determined if the depressed keyis the numeric key “7”, in step 222. If yes, microprocessor 16 connectsemergency call unit 10 for communication between the called person andthe caller via speaker 26 and microphone 58, in step 224, for apredetermined limited time such as 90 seconds. For example, the calledperson can then assure the caller that help is on the way. The callercan then pick up the telephone and speak with the called person for aslong as the caller desires. If this occurs, an off hook conditionexists. It is therefore sensed in step 225 if an off hook conditionexists in step 225. If no, the caller can end the communication but notthe connection, by pressing the pound (#) key on keypad 30. This isdetermined in step 226. If the pound (#) key is pressed, the processcontinues to step 234 discussed hereinafter. If the pound (#) key is notpressed, it is next determined if the predetermined limited time hasexpired in step 227. If no, the process returns to step 225, and if yes,the process continues to step 234. Alternatively, instead of enablingcommunications, unit 10 can merely provide a signal such as an audiblealarm or the like to the caller to indicate that the called personreceived the message. Alternatively, the above arrangement can beprovided where the caller can speak for 15 seconds, followed by thecalled party speaking for 15 seconds, and so on.

In step 225, if the caller picks up the telephone, an off hook conditionis detected, and the process continues to step 229, where it isdetermined if the caller has hung up the telephone. If no, a loop isprovided back to the input of step 229 to periodically make thisinquiry. If the person has hung up, the process continues to step 231 todetermine if a predetermined time period of for example, one-half hourhas elapsed. This step is provided in the event that the caller cannothang up the telephone that is picked up, and more than one-half hourpasses when paramedics or others come to the aid of the caller and hangup the telephone. In such case, since the caller has been helped, thesystem should not start dialing the emergency telephone numbers again,since this would create a false emergency call. Thus, if the time haselapsed, the process continues to step 228 which is discussedhereinafter, to end the call process. If the time has not elapsed, forexample, the caller hangs up within the time period, the processcontinues to step 212, to start dialing other telephone numbers on thelist.

In step 222, if it is determined that the numeric key “7” has not beendepressed, it is then determined if the depressed key is the numeric key“8”, in step 234. If yes, emergency call unit 10 hangs up in step 228,and then powers down the unit in 230 so that no further telephonenumbers are dialed. This is because the message has been received by oneperson who can take action. Alternatively, in a preferred embodiment,rather than powering down, emergency call unit 10 can be programmed todial the remaining numbers (or one or more further numbers) and leavemessages. Preferably, if numeric key “8” is not depressed by any of thecalled numbers, emergency call unit 10 will continue to dial through allof the numbers more than one time, for example, two, three or more timesuntil an appropriate response is received. The alternative operationlimits this to dialing through the telephone numbers only once.Preferably, regardless of which alternative is used when numeric key “8”is depressed, a recognition signal, such as a tone or voice, will besent to the caller to acknowledge that the message has been received.

In step 234, if it is determined that the numeric key “8” has not beendepressed by the called person, it is determined in step 236 whether thenumeric key “9” has been depressed. If yes, the process returns to step202 in order for the played messages to be re-played for the calledperson.

If not, the process proceeds to step 237 where it is determined if thenumeric key “5” has been depressed by the caller. If yes, the processreturns to step 228 to shut the system down. If no, the process returnsto step 210.

It is further noted that at any time in the CALL MODE, if the callerpicks up the telephone to talk to a called person or to call a person ina normal manner, the system is disabled since there is no dial tone instep 190, whereby emergency call unit 10 cannot dial any telephonenumber.

As a further alternative, the system provides the option of sending outa current message before the emergency message. This would be providedby a 4-5 seconds delay before the emergency message is sent. Thus, forexample, the caller can recite “My child just swallowed a bone” and hangup, whereupon the current message followed by the emergency messagewould be sent to all dialed numbers.

As discussed above, emergency call unit 10 and telephone unit 14 can beseparate connected units, or alternatively, can be a single integralunit. Further, emergency call keys E1, E2 and E3 can be activated fromthe emergency call unit 10 or from pendant 46.

Another feature of an emergency call unit 10 in accordance with theinvention is designed for situations where a person is using aspeakerphone feature on the emergency call unit 10 or on a telephoneassociated with the emergency call unit 10, and then presses anemergency key. In this case, the microprocessor 16 is programmed toimmediately terminate the call by turning the speakerphone feature offand then initiate one of the dialing sequences described above. Thisfeature can be applied to an emergency call system independent from thedialing sequences described above, i.e., on connection with any type ofdialing sequence.

In the delay mode, the microprocessor 16 would wait sixteen seconds toassure that the call for which the speakerphone feature was being usedwas terminated and could not be re-established and then six seconds toassure that there are no incoming calls. To possibly eliminate therequirement of waiting sixteen seconds when the call was an outgoingcall initiated by the person who is initiating the emergency call unit10, the microprocessor 16 can be designed to detect whether the call isincoming or outgoing. For an incoming call, the sixteen second wait isrequired to account for calling party control whereas for an outgoingcall, the sixteen second delay is not required since turning thespeakerphone feature off or hanging up the handset ends calling partycontrol over that call. As such, if the call was outgoing and made usingthe emergency call unit 10, as soon as the person presses the emergencykey, the emergency call unit 10 can be programmed to proceed directly tothe delay for incoming calls.

Another feature that can be incorporated into the emergency call unit 10when incorporated into a telephone base unit is that if that telephoneis off hook when an emergency key is pressed, the microprocessor 16 canbe designed to detect the off hook condition and electronicallyre-connect the telephone so that an outgoing call can be made. Themicroprocessor 16 would bypass the handset and disregard the fact thatthe handset is not connected to the telephone base. This feature isparticularly useful since in prior art devices, an off hook telephoneprevented use of the system. This feature can be applied to an emergencycall system independent from the dialing sequences described above,i.e., on connection with any type of dialing sequence.

Another feature that can be incorporated into the emergency call unit 10in any of the variations discussed above is a reset feature which, afterthe preset telephone numbers are all dialed, resets the emergency callunit 10 to allow for incoming calls and specifically, when the telephoneis off hook (i.e., the handset is not in its proper position on thebase), activates the speakerphone to enable reception of incoming calls.Control over the speakerphone can be accomplished via programming of themicroprocessor 16. Applying this feature, even if the handset is offhook during the dialing sequence, once the numbers in the list have beendialed, incoming calls can be received with the ring signal sequencebeing heard via the speakerphone. This overcomes the problem of anindividual leaving the handset off the hook, which would otherwiseprevent them from receiving incoming calls responsive to the outgoingemergency messages.

Thus, an emergency call system according to the present inventioneliminates the requirement for a central station, and eliminates therequirement for a separate wiring of the caller's home. Also, emergencycall system can be used with a conventional telephone line. With such anarrangement, emergency call system is inexpensive and easy to make,install and operate.

As part of the description above relating to the delay mode for dialingusing emergency call unit, a routine is described which can moregenerally be used whenever it is desired to make an outgoing callwithout detecting a dial tone. This dialing routine can be implementedin a microprocessor of a communications unit mounting in a housing in asimilar manner as the routine for the delay mode is implemented inmicroprocessor 16. However, the dialing routine, and dialer implementingit, is not limited to use with an emergency call system and can be usedfor any other telecommunications device.

Such a dialer in accordance with the invention for making an outgoingcall would basically comprise a housing and a communications unitarranged therein and coupled to the telephone line. The communicationsunit includes a microprocessor arranged to receive a command to initiatean outgoing call on the telephone line to a telephone number, withoutfirst detecting a dial tone, delay dialing of the telephone number for aperiod of time to assure that the outgoing call can be made on thetelephone line, and then dial the telephone number after the delay. Themicroprocessor generates the delay using the flow chart shown in FIG.4H, first checking to make sure the previous call is not subject tocalling party control and then making sure that there is no incomingcall. Details of the manner in which these delays are implemented aredescribed above.

Having described a specific preferred embodiment of the invention withreference to the accompanying drawings, it will be appreciated that thepresent invention is not limited to that precise embodiment, and thatvarious changes and modifications can be effected therein by one ofordinary skill in the art without departing from the scope or spirit ofthe invention as defined by the appended claims.

1. A dialer for making outgoing call, comprising: a housing; and a communications unit arranged in said housing and coupled to the telephone line, said communications unit including a microprocessor arranged to: receive a command to initiate an outgoing call on the telephone line to a telephone number, without first detecting a dial tone, delay dialing of the telephone number for a period of time to assure that the outgoing call can be made on the telephone line, and then dial the telephone number after the delay.
 2. The dialer of claim 1, wherein said microprocessor generates the delay by: starting a first timer, checking whether any telephone or device connected to the telephone line is off hook, restarting the first timer when a telephone or device is determined to be off hook, and when a telephone or device is not off hook, determining whether a first predetermined period of time has elapsed or a ring signal is detected and if not repeating the hook checking step, the timer restarting check and the determination step.
 3. The dialer of claim 2, wherein the first predetermined period of time is set to a time a telephone company maintaining the telephone line allots for a call to resume after the called party hangs up their telephone.
 4. The dialer of claim 2, wherein the first predetermined period of time is eight to twenty seconds, preferably sixteen seconds.
 5. The dialer of claim 2, wherein said microprocessor generates the delay by further: monitoring the telephone line for silence after determining whether the first predetermined period of time has elapsed or the ring signal has been detected and enabling each the telephone number to be dialed, without first detecting a dial tone, only after a period of silence is detected which is greater than the quiet period within a ring signal sequence indicative of an incoming call.
 6. The dialer of claim 2, wherein after a determination is made that the first predetermined period of time has elapsed or the ring signal has been detected, said microprocessor generates the delay by further: starting a second timer, checking whether any telephone or device connected to the telephone line is off hook, restarting the second timer when a telephone or device is determined to be off hook, when a telephone or device is not off hook, determining whether a second predetermined period of time has elapsed and if not determining whether a ring signal is present, and when a ring signal is not present, repeating the hook checking step and the determination step.
 7. The dialer of claim 6, wherein when the second period of time has elapsed, said microprocessor places the emergency call unit in an off hook condition, retrieves the telephone number and then dials it.
 8. The dialer of claim 6, wherein when the ring signal is present, said microprocessor generates the delay by further repeating the second timer starting step, the hook checking step and the determination step.
 9. The dialer of claim 6, wherein when the second period of time is based on a quiet period within a ring signal sequence and is typically six seconds.
 10. The dialer of claim 1, wherein said microprocessor generates the delay by: determining whether a first predetermined period of time has elapsed or a ring signal is detected and enabling the telephone number to be dialed, without first detecting a dial tone, only after the first period of time has elapsed or the ring signal has been detected.
 11. The dialer of claim 10, wherein said microprocessor further generates the delay by: monitoring the telephone line for silence after determining whether the first predetermined period of time has elapsed or the ring signal has been detected and enabling each of the telephone numbers to be dialed, without first detecting a dial tone, only after a period of silence is detected which is greater than the quiet period within a ring signal sequence indicative of an incoming call. 